Effect of including canola meal and supplemental iodine in diets of dairy cows on short-term changes in iodine concentrations in milk

Abstract

The dietary requirement for iodine is based on thyroxine production, but data are becoming available showing potential improvements in hoof health when substantially greater amounts of I are fed. Feeding high amounts of I, however, can result in the milk having excessive concentrations of I. Canola meal contains goitrogenic compounds that reduce the transfer of I into milk. We hypothesized that including canola meal in diets would allow high supplementation rates of I without producing milk with unacceptable concentrations of I. Thirty midlactation Holstein cows were fed a diet with all supplemental protein from soybean meal (0% of diet dry matter as canola meal) or with all supplemental protein from canola meal (13.9% canola meal). A third treatment has a mix of soybean meal and canola meal (3.9% canola meal). Within canola-meal treatment, cows were fed 0.5 or 2.0mg of supplemental I per kilogram of diet dry matter from ethylenediamine dihydroiodide. Cows were maintained on the canola treatment for the duration of the experiment but were changed from one I treatment to the other after 13d of receiving the treatment. Milk I concentration before the treatments started (cows fed 0.5mg/kg of I) averaged 272μg/L and increased within 22h after cows were first fed diets with 2mg/kg of I. As inclusion rate of canola meal increased, the concentration of I in milk decreased linearly. After 12d of supplementation, milk from cows fed 0.5mg/kg of I had 358, 289, and 169μg of I/L for the 0, 3.9%, and 13.9% canola-meal treatments. For cows fed 2.0mg/kg of I, milk I concentrations were 733, 524, and 408μg/L, respectively. Concentrations of I in serum increased with increased I supplementation, but the effect of canola meal was opposite of what was observed for milk I. Cows fed the highest canola-meal diets had the highest serum I whether cows were fed 0.5 or 2.0mg/kg of I. Feeding dairy cows diets with 13.9% canola meal maintained milk I concentrations below 500μg/L when diets were supplemented with 2mg/kg of I.

Use of indirect calorimetry to evaluate utilization of energy in lactating Jersey dairy cattle consuming common coproducts

“…Dried distillers grains have been reported to contain rumen-available UFA, which can contribute to milk fat depression . Weiss et al (2015) reported milk fat to linearly increase from 3.28 to 3.34% when canola meal in the diet was increased from 3.9 to 13.9% and fed to Holstein dairy cattle. The results of our study suggest that milk fat can be maintained when DDGS containing varying crude fat levels and canola meal are replace corn and soybean meal at 10% of the diet.…”

Influence of Iodine Feeding on Microbiological and Physico-Chemical Characteristics and Biogenic Amines Content in a Raw Ewes’ Milk Cheese

“…Nudda et al [ 6 ] reported that the iodine supplementation in dairy goat diets doubled the milk iodine content when compared with the control group, even if no evident effect was observed in the gross composition of milk. On the contrary, Weiss et al [ 7 ] found that iodine concentration increased in serum but not in milk after supplementation of this element in diets of dairy cows. In fact, very little information is available about the effects of iodine addition on ewes’ milk and milk-based product composition, nor about the response of dairy product microbiota.…”

“…Changes in animal feeding have been proposed as one of the most promising approaches to modify iodine content in milk [ 5 ]. Some studies [ 6 , 7 ] have been carried out to evaluate the effects of dietary iodine supplementation in dairy goats and cows on milk iodine content and milk production traits. Nudda et al [ 6 ] reported that the iodine supplementation in dairy goat diets doubled the milk iodine content when compared with the control group, even if no evident effect was observed in the gross composition of milk.…”

Iodine Status and Consumption of Key Iodine Sources in the U.S. Population with Special Attention to Reproductive Age Women

“…The contribution of these food sources to total iodine intake may be slightly overstated, as they do not account for iodine from supplements, water, or iodized salt, which can contribute between 10–20% of iodine intake [ 14 ]. The iodine content in dairy milk can vary widely [ 15 ], depending on the iodine content in cattle feed, teat-dipping practices before and after milking [ 16 ], and the presence of goitrogens (substances that can block the uptake or utilization of iodine in cattle feed [ 17 ]). Other common food sources of iodine include grains and eggs [ 10 , 18 ].…”